19 Select the correct answer.
George owns a juice manufacturing unit. He conducts a cardiopulmonary resuscitation training program every six months for his employees.
George is following guidelines set by which US authority?
A.
Occupational Safety and Health Administration
B.
Compensation and Liability Act
C.
Clean Air Act
D.
Fair Labor Standards Act

answer: you could do some invislibe ink.

explanation: i will tell you how to if u answer my question.

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.